Electric iron sole plate

ABSTRACT

Sole plate for pressing iron whose pressing surface comprises a coating improving the sliding of the iron on the materials to be pressed. The coating comprises an underlayer of satin-finished nickel and a surface layer of chromium. The underlayer of satin-finished nickel has a thickness comprised between 5 and 15 microns and the surface layer of chromium has a thickness comprised between 0.06 and 0.3 micron. The outer surface of the coating has a rugosity of at least 30.

FIELD OF THE INVENTION

The present invention relates to a sole plate for an electric ironadapted to be fixed to a heating body and whose pressing surfacecomprises a coating improving the sliding of the iron on the material tobe ironed.

BACKGROUND OF THE INVENTION

The prior art teaches the provision of many such coatings, thusreflecting the constant care for seeking a material with a very lowcoefficient of friction to iron all cloth. By way of example can becited the following coatings: polytetrafluorethylene, enamel, ceramic,stainless steel, chromium, etc.

The applicant has particularly used for a number of years in pressingirons known as OPTIMATE, ULTIMATE, a coating comprising a layer ofbrilliant nickel covered with a deposit of chromium. Such a coating isknown to offer for the most part a high coefficient of sliding over mostcloth, as well as an outstanding appearance thanks to its extremelysmooth and brilliant surface. However, this smooth surface is not idealand has, not only a sensitivity to cracking due to mechanical shockseither during production or during improper use, but also a frictionwhich is too high, on synthetic fabric such as polyesters.

OBJECT OF THE INVENTION

The object of the present invention is therefore to overcome thedrawbacks mentioned above by providing particularly a coating that willbe practically universal for pressing of all cloth by improvingsubstantially the sliding on polyesters.

SUMMARY OF THE INVENTION

According to the invention, the coating comprises an underlayer ofsatin-finished nickel, and a surface layer of chromium.

According to the applicant, the particular advantage of this coating isdue to the typography of its external surface, which has a parameter ofrugosity Ra substantially greater than that obtained with a brilliantnickel coating and which is of a ratio at least equal to 30.

Tests carried out by the applicant convincingly prove that the slidingof the sole plate is inversely proportional to the parameter Ra.Micrographic analyses of the typography of the coating show clearly thatit has a myriad microcavities, which by interaction with the steamgenerated during pressing, give rise to an astounding improvement insliding of the sole plate over all cloth, and particularly polyesters.

DETAILED DESCRIPTION OF THE INVENTION

So as better to understand the invention, there will be given hereafterone example of embodiment of such a sole plate.

The pressing iron comprises a sole plate constituted by a steel supportand comprises on its pressing surface a coating improving sliding. Thisiron can be either of the dry type, or of the steam type, and its soleplate in that case comprises several holes for the escape of steam.

According to the invention, the coating comprises an underlayer ofsatin-finished nickel and a surface layer of chromium.

Thus, the applicant, by constant efforts of research for new materials,has discovered surprisingly a new application of satin-finished nickelwhich is a material known to those skilled in the art for otherindustrial applications and which is described for example in thepamphlet “Electrolytic nickeling” in the “ORGANO GALVANO” review, byLouis Lacourcelle, under the reference: Pamphlet 52 “Information for theUse of the Designer”.

According to an important characteristic of the invention, theunderlayer of satin-finished nickel has a thickness comprised between 5and 15 microns, and, in the example of embodiment, a thickness of 11microns.

So as to increase the resistance to corrosion, a surface layer ofchromium has a thickness comprised between 0.06 and 0.3 micron.

To permit good bonding of the satin-finished nickel layer to the steelsupport, there is moreover provided a deposit of mat nickel in contactwith said support and an acid deposit of copper for bonding to thesatin-finished nickel.

These different deposits recited above are carried out by electrolyticdeposition as is well known to those in the art. Reference can again behad to the pamphlet described above which summarizes three processes,namely: with the addition of argon additives; with inert particles; withemulsions formed of small droplets of oil.

One of the preferred processes of the invention consists in carrying outthe following steps beginning with a steel sole plate:

a) chemical degreasing of the sole plate

b) pickling

c) electro-cathodic/anodic degreasing

d) deposition of mat nickel

e) acid deposition of copper

f) deposition of satin-finished nickel

g) deposition of chromium

The depositions according to steps d, e, f and g last between 5 and 15minutes at a bath temperature of the order of 30 to 65° C. withmechanical agitation and a PH comprised between 3 and 7.

Compared to the coatings of the prior art, particularly to that appliedby the applicant involving brilliant nickel and chromium, there is noteda surprising improvement of the sliding of the iron sole plateparticularly on polyesters, as can be seen from the following table.

Comparative Force of Traction (in Grams)

Brilliant Satin-finished Types of cloth nickel/chromium nickel/chromiumPolyester 507 219 Polyester-cotton 367 202 Polyester-linen 231 203 Linen190 173 Cotton 280 220

This table shows clearly that the frictional force measured in grams is,for the sole plate according to the invention, particularly decreasedand even by the order of two times less for polyester-based cloth.

What is claimed is:
 1. Sole plate for pressing iron whose pressingsurface comprises a coating improving the sliding of the iron on thematerials to be pressed, characterized in that the coating comprises anunderlayer of satin-finished nickel and a surface layer of chromium. 2.Sole plate according to claim 1, characterized in that the underlayer ofsatin-finished nickel has a thickness comprised between 5 and 15microns.
 3. Sole plate according to claim 2, characterized in that thesurface layer of chromium has a thickness comprised between 0.06 and 0.3micron.
 4. Sole plate according to claim 3, characterized in that thecoating is applied to a steel support.
 5. Sole plate according to claim4, characterized in that, between the support and the underlayer ofsatin-finished nickel, the coating comprises moreover a deposition ofmat nickel in contact with the support and an acid deposition of copperfor bonding to the satin-finished nickel.
 6. Sole plate according toclaim 1, characterized in that the coating is carried out byelectrolytic deposition.
 7. Sole plate according to claim 1,characterized in that it is mounted on a steam iron.
 8. Sole plateaccording to claim 1, characterized in that the surface layer ofchromium has a thickness comprised between 0.06 and 0.3 micron.
 9. Soleplate according to claim 2, characterized in that the coating is appliedto a steel support.